"I started the show being a singer and a musician, and so I'm going to go back to that," Lovato said. "It's been really great, but I'm so excited for 2014. I'm going to dedicate it completely and entirely to music -- touring and making a new album. Possibly releasing one."

She also spoke about what she would miss most about her X Factor time: "Being able to sit next to Kelly and Paulina and see them twice a week, and also helping mentor the contestants."

The show's schedule conflicts with Lovato's plans to spend the next year completely focused on her music, a source close to the singer told Peopleearly on Wednesday.

Lovato, who has been recurring on Fox's Glee this season, is set to begin her Neon Lights tour to support her latest album, Demi, on Feb. 9 in Vancouver. The arena trek, supported by artists with X Factor ties -- Cher Lloyd, Fifth Harmony and Little Mix -- will run through the end of March.

Lovato is also working on a memoir following the November release of her book, Staying Strong: 365 Days a Year.

Lovato and X Factor mastermind Cowell were the only two judges from the show's second season to return for its third season amid a major overhaul that included the exits of Britney Spears and L.A. Reid. She and Cowell joined new additions Kelly Rowland and Paulina Rubio. This season's X Factor finale airs on Thursday at 8 p.m.

In May Lovato talked to Billboard about why she opted to do another season of the show instead of supporting her album on tour in 2013.

"When you have the opportunity to be in front of America every single week several times a week, that's a very incredible opportunity, not only because your fans get to know you better, but … I was on the Disney Channel forever, and was waiting for that right job that would help me cross over to the mainstream world. I was not only in front of my fans every week, but I was also in front of adults. I never used to get recognized by adults, and now when I'm at the airport or the grocery store, the guy behind the register will be like, 'I love you on X Factor!' It's really awesome to have expanded my fan base," she said.

Meanwhile, X Factor's future remains unclear. Cowell told reporters Monday during a conference call that he thought the show "will be coming back next year." Also unclear will be his role with the low-rated series. "I might have a different kind of role -- we haven't discussed that yet," he said, noting that the judging panel and the show's format would likely undergo some changes should the series return.